William Angus Drogo Montagu, 9th Duke of Manchester PC (3 March 1877 – 9 February 1947), styled Lord Kimbolton from 1877 to 1890 and Viscount Mandeville from 1890 to 1892, was a British peer and Liberal politician.

He was the only legitimate son of The 8th Duke of Manchester, by his wife Consuelo Yznaga del Valle, a Cuban American heiress.

[6] Manchester succeeded his father in the dukedom in 1892 at the age of fifteen, and took his seat on the Liberal benches in the House of Lords in June 1902.

[9] In 1914 he and his then wife were guests aboard Vanderbilt's steam yacht Warrior when it ran aground in a heavy sea on the Caribbean coast of Colombia.

[12] He is perhaps most well known in America from the leading case of Hamilton v. Drogo, which concerned the establishment of a spendthrift trust for the benefit of the young Duke.

[2] The Duke of Manchester died at Seaford, East Sussex, on 9 February 1947, aged 69, and was succeeded in his titles by his son Alexander.